Indoor positioning refers to techniques whereby the position of a wireless user device can be determined with respect to a location network comprising multiple anchor radios, the anchors being wireless nodes whose positions are known a priori (typically being recorded in a location database). Various measurements of the signals transmitted between the mobile device and anchor nodes may be employed to obtain the device's position, such as the RSSI (receiver signal strength indicator), ToA (time of arrival) and AoA (Angle of arrival). The determination of the device's position may be achieved using measurements made and processed at the device (a “device-centric” implementation) or using measurements made and processed at the location network (a “network-centric” implementation).
In the context of lighting systems, one application of indoor positioning is to automatically provide a wireless mobile device with access to control of the lighting system when that mobile device is found to be positioned in a particular spatial region associated with the lighting. For instance, access to control of the lamps in a room may be provided to a wireless user device if the device is found to be positioned inside that room and requests access. Once a wireless user device is positioned and determined to be within a valid region, control access is provided to that device via a lighting control network.
WO2004/023849 discloses a lighting control system and a method of controlling lights that involves two-way wireless communication, wherein the two-way wireless communication is used for pairing a remote control device to one or more ballasts of the lighting system.
US2011/0140864 discloses a system and method for identifying and categorizing distributed devices, that involves localization of a device and the association of an identifier with the device. The method involves a portable programming tool sending a low-power discovery message to the distributed devices. The devices in range respond with identification information. The portable programming tool organizes the responses based on proximity and sends a “flash” message to the device closest. In response that device responds and the user confirm that this is the device that he intended and can store the identifier and e.g. location of the device for later use, such as load shedding or the reduction of power consumption.